Safeguarding personal digital data is crucial and requires appropriate training. However, privacy remains a novel topic, leaving teachers with limited guidance. This study investigates how elementary school students perceive personal data and assesses pre-service teachers' accuracy in predicting children's responses. Employing Nissenbaum's contextual integrity framework, the outcomes of this research offer a nuanced perspective on privacy, considering different recipients and data types. The study surveyed 94 Grade 3 and Grade 5 students, asking them to indicate with which recipients (no one, parents, best friends, class, all other people) they would share specific information. In addition, 75 pre-service teachers were asked to indicate what they expected Grade 5 children would share with whom. The findings show: 1. what information Grade 3 and Grade 5 students consider to be most private, 2. which recipients they trust the most, 3. varying sharing practices between Grade 3 and 5, and 4. a tendency for pre-service teachers to underestimate children's privacy sharing behavior. In the discussion section we propose five recommendations for enhancing digital privacy education.